1421065665 has 12 divisors (see below), whose sum is σ = 2463180564. Its totient is φ = 757901664.

The previous prime is 1421065663. The next prime is 1421065691. The reversal of 1421065665 is 5665601241.

It can be written as a sum of positive squares in 2 ways, for example, as 565678656 + 855387009 = 23784^2 + 29247^2 .

It is not a de Polignac number, because 1421065665 - 2¹ = 1421065663 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1421065661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 15789574 + ... + 15789663.

It is an arithmetic number, because the mean of its divisors is an integer number (205265047).

Almost surely, 2^1421065665 is an apocalyptic number.

1421065665 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1421065665 is a deficient number, since it is larger than the sum of its proper divisors (1042114899).

1421065665 is a wasteful number, since it uses less digits than its factorization.

1421065665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31579248 (or 31579245 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 36.

The square root of 1421065665 is about 37697.0246173355. The cubic root of 1421065665 is about 1124.2719674812.

The spelling of 1421065665 in words is "one billion, four hundred twenty-one million, sixty-five thousand, six hundred sixty-five".